The YvqE two-component system controls biofilm formation and acid production inStreptococcus pyogenes

Apmis ◽  
2016 ◽  
Vol 124 (7) ◽  
pp. 574-585 ◽  
Author(s):  
Masanori Isaka ◽  
Ichiro Tatsuno ◽  
Jun-Ichi Maeyama ◽  
Hideyuki Matsui ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Acid Production ◽  
Two Component System ◽  
Component System ◽  
Two Component

scholarly journals Autoinducer-2 and QseC Control Biofilm Formation and In Vivo Virulence of Aggregatibacter actinomycetemcomitans

2010 ◽  
Vol 78 (7) ◽  
pp. 2919-2926 ◽  
Author(s):  
Elizabeth A. Novak ◽  
HanJuan Shao ◽  
Carlo Amorin Daep ◽  
Donald R. Demuth
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Biofilm Formation ◽  
Alveolar Bone ◽  
Wild Type ◽  
Two Component System ◽  
Component System ◽  
Autoinducer 2 ◽  
Two Component

ABSTRACT Biofilm formation by the periodontal pathogen Aggregatibacter actinomycetemcomitans is dependent upon autoinducer-2 (AI-2)-mediated quorum sensing. However, the components that link the detection of the AI-2 signal to downstream gene expression have not been determined. One potential regulator is the QseBC two-component system, which is part of the AI-2-dependent response pathway that controls biofilm formation in Escherichia coli. Here we show that the expression of QseBC in A. actinomycetemcomitans is induced by AI-2 and that induction requires the AI-2 receptors, LsrB and/or RbsB. Additionally, inactivation of qseC resulted in reduced biofilm growth. Since the ability to grow in biofilms is essential for A. actinomycetemcomitans virulence, strains that were deficient in QseC or the AI-2 receptors were examined in an in vivo mouse model of periodontitis. The ΔqseC mutant induced significantly less alveolar bone resorption than the wild-type strain (P < 0.02). Bone loss in animals infected with the ΔqseC strain was similar to that in sham-infected animals. The ΔlsrB, ΔrbsB, and ΔlsrB ΔrbsB strains also induced significantly less alveolar bone resorption than the wild type (P < 0.03, P < 0.02, and P < 0.01, respectively). However, bone loss induced by a ΔluxS strain was indistinguishable from that induced by the wild type, suggesting that AI-2 produced by indigenous microflora in the murine oral cavity may complement the ΔluxS mutation. Together, these results suggest that the QseBC two-component system is part of the AI-2 regulon and may link the detection of AI-2 to the regulation of downstream cellular processes that are involved in biofilm formation and virulence of A. actinomycetemcomitans.

scholarly journals The NarX-NarL two-component system is a global regulator of biofilm formation, natural product biosynthesis, and host-associated survival in Burkholderia pseudomallei

2020 ◽  
Author(s):  
Mihnea R. Mangalea ◽  
Bradley R. Borlee
Keyword(s):  
Gene Expression ◽  
Surface Waters ◽  
Biofilm Formation ◽  
Burkholderia Pseudomallei ◽  
Nitrosative Stress ◽  
Two Component System ◽  
Component System ◽  
Sensing System ◽  
Two Component ◽  
Nitrate And Nitrite

AbstractIn the environment, Burkholderia pseudomallei exists as a saprophyte inhabiting soils and surface waters where denitrification is important for anaerobic respiration. As an opportunistic pathogen, B. pseudomallei transitions from the environment to infect human and animal hosts where respiratory nitrate reduction enables replication in anoxic conditions. We have previously shown that B. pseudomallei responds to nitrate and nitrite in part by inhibiting biofilm formation and altering cyclic di-GMP signaling. Here, we describe the global transcriptomic response to nitrate and nitrite to characterize the nitrosative stress response relative to biofilm inhibition. To better understand the roles of nitrate-sensing in the biofilm inhibitory phenotype of B. pseudomallei, we created in-frame deletions of narX (Bp1026b_I1014) and narL (Bp1026b_I1013), which are adjacent components of the conserved nitrate-sensing two-component system. Through differential expression analysis of RNA-seq data, we observed that key components of the biofilm matrix are downregulated in response to nitrate and nitrite. In addition, several gene loci associated with the stringent response, central metabolism dysregulation, antibiotic tolerance, and pathogenicity determinants were significantly altered in their expression. Some of the most differentially expressed genes were nonribosomal peptide synthases (NRPS) and/or polyketide synthases (PKS) encoding the proteins for the biosynthesis of bactobolin, malleilactone, and syrbactin, in addition to an uncharacterized cryptic NRPS biosynthetic cluster. We also observed reduced expression of ribosomal structural and biogenesis loci, and gene clusters associated with translation and DNA replication, indicating modulation of growth rate and metabolism under nitrosative stress conditions. The differences in expression observed under nitrosative stress were reversed in narX and narL mutants, suggesting that nitrate sensing is an important checkpoint for regulating the diverse metabolic changes occurring in the biofilm inhibitory phenotype. Moreover, in a macrophage model of infection, narX and narL mutants were attenuated in intracellular replication, suggesting that nitrate sensing is important for host survival.Author SummaryBurkholderia pseudomallei is a saprophytic bacterium inhabiting soils and surface waters throughout the tropics causing severe disease in humans and animals. Environmental signals such as the accumulation of inorganic ions mediates the biofilm forming capabilities and survival of B. pseudomallei. In particular, nitrate metabolism inhibits B. pseudomallei biofilm formation through complex regulatory cascades that relay environmental cues to intracellular second messengers that modulate bacterial physiology. Nitrates are common environmental contaminants derived from artificial fertilizers and byproducts of animal wastes that can be readily reduced by bacteria capable of denitrification. In B. pseudomallei 1026b, biofilm dynamics are in part regulated by a gene pathway involved in nitrate sensing, metabolism, and transport. This study investigated the role of a two-component nitrate sensing system, NarX-NarL, in regulating gene expression, biofilm formation, and cellular invasion. Global gene expression analyses in the wild type, as compared to Δ narX and Δ narL mutant strains with nitrate or nitrite implicate the NarX-NarL system in the regulation of biofilm components as well as B. pseudomallei host-associated survival. This study characterizes a conserved nitrate sensing system that is important in environmental and host-associated contexts and aims to bridge a gap between these two important B. pseudomallei lifestyles.

scholarly journals The NarX-NarL two-component system regulates biofilm formation, natural product biosynthesis, and host-associated survival in Burkholderia pseudomallei

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Mihnea R. Mangalea ◽  
Bradley R. Borlee
Keyword(s):  
Biofilm Formation ◽  
Burkholderia Pseudomallei ◽  
Severe Disease ◽  
Expression Patterns ◽  
Inorganic Ions ◽  
Two Component System ◽  
Component System ◽  
Environmental Signals ◽  
Two Component ◽  
Nitrate And Nitrite

AbstractBurkholderia pseudomallei is a saprophytic bacterium endemic throughout the tropics causing severe disease in humans and animals. Environmental signals such as the accumulation of inorganic ions mediates the biofilm forming capabilities and survival of B. pseudomallei. We have previously shown that B. pseudomallei responds to nitrate and nitrite by inhibiting biofilm formation and altering cyclic di-GMP signaling. To better understand the roles of nitrate-sensing in the biofilm inhibitory phenotype of B. pseudomallei, we created in-frame deletions of narX (Bp1026b_I1014) and narL (Bp1026b_I1013), which are adjacent components of a conserved nitrate-sensing two-component system. We observed transcriptional downregulation in key components of the biofilm matrix in response to nitrate and nitrite. Some of the most differentially expressed genes were nonribosomal peptide synthases (NRPS) and/or polyketide synthases (PKS) encoding the proteins for the biosynthesis of bactobolin, malleilactone, and syrbactin, and an uncharacterized cryptic NRPS biosynthetic cluster. RNA expression patterns were reversed in ∆narX and ∆narL mutants, suggesting that nitrate sensing is an important checkpoint for regulating the diverse metabolic changes occurring in the biofilm inhibitory phenotype. Moreover, in a macrophage model of infection, ∆narX and ∆narL mutants were attenuated in intracellular replication, suggesting that nitrate sensing contributes to survival in the host.

scholarly journals EmbRS a new two‐component system that inhibits biofilm formation and saves R ubrivivax gelatinosus from sinking

2013 ◽  
Vol 2 (3) ◽  
pp. 431-446 ◽  
Author(s):  
Anne Soisig Steunou ◽  
Sylviane Liotenberg ◽  
Marie‐Noêlle Soler ◽  
Romain Briandet ◽  
Valérie Barbe ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Two Component System ◽  
Component System ◽  
Two Component

Involvement of PhoP/PhoQ two-component system in biofilm formation in Cronobacter sakazakii

Food Control ◽  
2021 ◽  
pp. 108621
Author(s):  
Yan Ma ◽  
Yingying Zhang ◽  
Zhongguo Shan ◽  
Xin Wang ◽  
Xiaodong Xia
Keyword(s):  
Biofilm Formation ◽  
Cronobacter Sakazakii ◽  
Two Component System ◽  
Component System ◽  
Two Component

scholarly journals Effects of Oxygen on Biofilm Formation and the AtlA Autolysin of Streptococcus mutans

2007 ◽  
Vol 189 (17) ◽  
pp. 6293-6302 ◽  
Author(s):  
Sang-Joon Ahn ◽  
Robert A. Burne
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Normal Cell ◽  
Surface Protein ◽  
Two Component System ◽  
Component System ◽  
Oxidative Stress Tolerance ◽  
Two Component ◽  
Causative Agents

ABSTRACT The Streptococcus mutans atlA gene encodes an autolysin required for biofilm maturation and biogenesis of a normal cell surface. We found that the capacity to form biofilms by S. mutans, one of the principal causative agents of dental caries, was dramatically impaired by growth of the organism in an aerated environment and that cells exposed to oxygen displayed marked changes in surface protein profiles. Inactivation of the atlA gene alleviated repression of biofilm formation in the presence of oxygen. Also, the formation of long chains, a characteristic of AtlA-deficient strains, was less evident in cells grown with aeration. The SMu0629 gene is immediately upstream of atlA and encodes a product that contains a C-X-X-C motif, a characteristic of thiol-disulfide oxidoreductases. Inactivation of SMu0629 significantly reduced the levels of AtlA protein and led to resistance to autolysis. The SMu0629 mutant also displayed an enhanced capacity to form biofilms in the presence of oxygen compared to that of the parental strain. The expression of SMu0629 was shown to be under the control of the VicRK two-component system, which influences oxidative stress tolerance in S. mutans. Disruption of vicK also led to inhibition of processing of AtlA, and the mutant was hyperresistant to autolysis. When grown under aerobic conditions, the vicK mutant also showed significantly increased biofilm formation compared to strain UA159. This study illustrates the central role of AtlA and VicK in orchestrating growth on surfaces and envelope biogenesis in response to redox conditions.

scholarly journals Novel Two-Component System ofStreptococcus sanguinisAffecting Functions Associated with Viability in Saliva and Biofilm Formation

2018 ◽  
Vol 86 (4) ◽  
Author(s):  
Tarsila M. Camargo ◽  
Rafael N. Stipp ◽  
Lívia A. Alves ◽  
Erika N. Harth-Chu ◽  
José F. Höfling ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Ex Vivo ◽  
Opportunistic Pathogen ◽  
Dna Looping ◽  
Extracellular Dna ◽  
Two Component System ◽  
Component System ◽  
Content Type ◽  
Cell Counts ◽  
Two Component

ABSTRACTStreptococcus sanguinisis a pioneer species of teeth and a common opportunistic pathogen of infective endocarditis. In this study, we identified a two-component system,S. sanguinisSptRS (SptRSSs), affectingS. sanguinissurvival in saliva and biofilm formation. Isogenic mutants ofsptRSs(SKsptR) andsptSSs(SKsptS) showed reduced cell counts inex vivoassays of viability in saliva compared to those of parent strain SK36 and complemented mutants. Reduced counts of the mutants in saliva were associated with reduced growth rates in nutrient-poor medium (RPMI) and increased susceptibility to the deposition of C3b and the membrane attach complex (MAC) of the complement system, a defense component of saliva and serum. Conversely,sptRSsandsptSSsmutants showed increased biofilm formation associated with higher levels of production of H2O2and extracellular DNA. Reverse transcription-quantitative PCR (RT-qPCR) comparisons of strains indicated a global role of SptRSSsin repressing genes for H2O2production (2.5- to 15-fold upregulation ofspxB,spxR,vicR,tpk, andackAinsptRSsandsptSSsmutants), biofilm formation, and/or evasion of host immunity (2.1- to 11.4-fold upregulation ofsrtA,pcsB,cwdP,iga, andnt5e). Compatible with the homology of SptRSswith AraC-type regulators, duplicate to multiple conserved repeats were identified in 1,000-bp regulatory regions of downstream genes, suggesting that SptRSsregulates transcription by DNA looping. Significant transcriptional changes in the regulatory genesvicR,spxR,comE,comX, andmecAin thesptRSsandsptSSsmutants further indicated that SptRSSsis part of a regulatory network that coordinates cell wall homeostasis, H2O2production, and competence. This study reveals that SptRSSsis involved in the regulation of crucial functions forS. sanguinispersistence in the oral cavity.

scholarly journals Role of PhoP-PhoQ Two-Component System in Biofilm Formation of the Phytopathogen Dickeya dadantii Strain 3937

2010 ◽  
pp. 108-117
Author(s):  
Md Manjurul Haque ◽  
Shinji Tsuyumu
Keyword(s):  
Biofilm Formation ◽  
Transcriptional Control ◽  
Test Tube ◽  
Luria Bertani ◽  
High Concentration ◽  
Two Component System ◽  
Dickeya Dadantii ◽  
Component System ◽  
Two Component

To elucidate the role of PhoP-PhoQ two-component system in biofilm formation by the phytopathogen Dickeya dadantii (formerly Erwinia chrysanthemi) strain 3937, we used marker-exchanged mutants deficient in both phoP and phoQ. A biofilm-inducing medium, salt-optimized broth plus glycerol (SOBG) which contains salt-optimized broth (SOB) plus 2% of glycerol, supported biofilm formation by D. dadantii strain 3937 to a greater extent than either M63 glycerol minimal medium or yeast extract peptone (YP) medium or Luria-Bertani (LB) medium. In addition, magnesium greatly induced biofilm formation. It was found that both the phoP and phoQ mutants exhibited enhanced ability to form a biofilm on the surface of the glass test tube as compared to the wild-type strain in SOBG medium containing high concentration of magnesium. In addition, under high magnesium condition, both the mutants produced elevated level of exopolysaccharide. Accordingly, genes responsible for exopolysaccharide production (weaP, wza and wzc) were derepressed in the mutants. These results suggest that the PhoP-PhoQ two-component system may regulate formation of biofilm, at least in part, by transcriptional control of genes responsible for exopolysaccharide biosynthesis of D. dadantii strain 3937. Since biofilm-associated bacteria showed more tolerance to acidic pH and high osmotic stress, it is apparent that the formation of biofilm may be an important factor for the survival of D. dadantii strain 3937 in unfavorable environment.

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